The liquid crystal display device is a device that controls whether to transmit/shield light by controlling the orientation of liquid crystal molecules having birefringent properties. Liquid crystal orientation modes in liquid crystal display devices include a twisted nematic (TN) mode in which liquid crystal molecules having positive dielectric anisotropy are aligned in a state of being twisted through 90° when viewed along the substrate normal direction, a vertical alignment (VA) mode in which liquid crystal molecules having negative dielectric anisotropy are aligned perpendicular to the substrate surface, an in-plane switching (IPS) mode in which the liquid crystal molecules having positive or negative dielectric anisotropy are aligned so as to be horizontal with respect to the substrate surface and a horizontal electric field is applied to the liquid crystal layer, and a fringe field switching (FFS) mode.
One widespread method for driving liquid crystal display devices is an active matrix driving method. According to this method, active devices such as thin-film transistors (TFTs) are provided at each pixel and a high image quality is realized. An array substrate including a plurality of TFTs and pixel electrodes has a plurality of pixel scan signal lines and a plurality of data signal lines that intersect with each other, and a TFT is provided at each intersection. Each TFT is connected to the pixel electrode and the supply of the image signal to the pixel electrode is controlled using the TFT switching function. The array substrate or an opposite substrate is further provided with a common electrode, and a voltage is applied within the liquid crystal layer via a pair of electrodes.
In IPS mode, which is one of the modes for controlling the orientation of the liquid crystal molecules by applying a lateral electric field, the pixel electrode and the common electrode are formed on the same substrate, and both electrodes are formed to have a plurality of comb-tooth projections. The comb-teeth projections of the pixel electrode and the comb-tooth projections of the common electrodes are parallel to each other. The orientation of the liquid crystal molecules is controlled based on the potential difference between the comb-teeth projections of the pixel electrode and the comb-tooth projections of the common electrode. The comb-tooth projections of the electrodes may be configured with a portion that is bent. By such a method it is possible to achieve excellent viewing angle characteristics (for example, see Patent Documents 1 to 3).